1. Technical Field of Invention
This invention relates to the production of resole resins and bonded laminates.
2. Description of Related Art
Ethylene glycol may be produced on an industrial scale by the hydrolysis of ethylene oxide in a large excess of water to obtain 85-90% monoethylene glycol (MEG). By-products produced in this reaction are lower polyglycols including diethylene, triethylene and tetraethylene glycols. The reaction effluent from the hydrolysis reaction is first treated in a series of multiple-effect evaporators to reduce its water content after which ethylene glycol (MEG) is refined by vacuum distillation. The residual or waste stream from the vacuum distillation tower typically comprises a polyglycol by-product content of from about 1 to about 2 wt % of the ethylene oxide utilized for the reaction and, to this extent, represents an economic wastage of ethylene oxide as well as presenting a disposal problem. In such glycol production unit waste streams, triethylene glycol (TEG) and tetraethylene glycol (Tetra EG) comprise the bulk of the polyglycol content of the waste stream.
Methanol may be produced on an industrial scale by the reaction of a synthesis gas, composed of carbon monoxide, hydrogen and some carbon dioxide, over an appropriate catalyst. The methanol product is recovered from the crude reaction mixture by distillation in a finishing column wherein at least 98 wt % of the methanol content of the column feed is recovered as a column overhead product which is 99.85 wt % or greater methanol, whereas the bottom stream from the column may account for about 2 wt % of the methanol content of the column feed in combination with a mixture of other alcohols and water. Typically this bottom stream on a weight basis comprises from about 45-65 wt % methanol; 10-20 wt % of mixed alcohols including ethanol, propanol, butanol and higher alcohols; and 15-45 wt % water. It is not economically practical to recover the methanol content from this bottom stream by further distillation, hence this content represents an economic wastage. The column bottoms pose a problem also with respect to their disposal in an environmentally sound manner.
As is the case with any industrial waste stream, it is always a desired goal in the art to discover a utilization for such materials which reduce or eliminate the problem of its disposal, and particularly to discover a utilization which is practical of an economic application.